Science writers like Gould, Goodenough, Sagan, or Dawkins often aspire to communicate the wonder they feel at the beauty, complexity, and diversity of nature. It’s a natural consequence of a career in science—perhaps even a prerequisite for one—to marvel at stars in the sky or strange creatures of the deep, or even the miracle of our own flesh. Great science writing tries to transmit that same sense of amazement to the reader. In return, all too often these writers are paid the backhanded compliment that they, who do not believe in spirits, are “spiritual;” that the joy they take in the universe is their “religion.”

“But is religion the right word?” asks eminent Oxford scholar Richard Dawkins in his newest book, The God Delusion(B&N). Though the appropriation of the term may seem innocuous, in Dawkins’s view it’s part of a larger and more dangerous trend. His reply—“I don’t think so”—sets the tone for the book.

This habit of confusing respect for nature with a belief in a higher power is convenient. It’s easy to take a scientist’s love of the cosmos or appreciation of humanity, slap the label “spiritual” on her rational, albeit appreciative, worldview and turn her into a poster child for religious belief. Albert Einstein was guilty of casually using the word “god” to refer to the impersonal forces of the universe, and his aphorisms are now routinely trotted out by the faithful. In fact, when Einstein clearly spelled out his disbelief in dogma, orthodoxy, organized religion, and a personal creator in a 1941 paper, he was publicly scorned and urged to silence himself, or return to Germany.

No one would ever mistake Dawkins for a friend of religion—or be shocked that he does not believe in gods. With his latest book he draws a hard, bright line and states unequivocally that he believes neither in the supernatural nor in any kind of deity. Dawkins rigorously outlines his rationale and takes it a step further: He suggests the reader think twice about adopting or harboring religious beliefs, going so far as to say, “If this book works for you, you will be an atheist when you put it down.” So be warned. Dawkins makes his case calmly, but his usual fierce clarity is ever-present. The God Delusion is a guide for secular evangelization, one that makes a direct assault on the premises of religion. Freethinkers will welcome it; the dogmatic will likely damn it as devil’s catechism; and people of faith will read it as a thoughtful challenge.

The first half of The God Delusion delivers a thorough overview of the logic of belief and disbelief. Dawkins reviews, dismantles, and dismisses the major arguments for the existence of the supernatural and deities; this section culminates in a chapter entitled “Why there almost certainly is no God.” Believers will not take solace in that “almost”—it’s a nod to the provisional nature of all scientific conclusions, not an admission that any evidence of God, however slight, exists and is under debate. Many of Dawkins’s arguments have been around for centuries, but he presents them in a fresh, lucid fashion.

The rest of The God Delusion is generally more speculative. If God or gods almost certainly do not exist, then why is religion so embedded in human culture? Dawkins sketches a review of some possible answers, but his preferred hypothesis is this: Religion does not confer a direct adaptive advantage, but is instead a byproduct of some other property that is useful for survival. Dawkins suggests that the root of religion lies in the efficiency of a shortcut. In childhood, a bit of credulity and the ability to mind one’s elders are extremely useful traits. Trial-and-error learning can be expensive—consider the cost of, for instance, learning firsthand why not to swim with crocodiles. To trust and obey authority figures is far preferable. The idea is interesting, but Dawkins overlooks another potential determinant: Empathy. It is both an extremely useful skill for navigating the complex social landscapes of human culture (so useful that it is taken for granted), and it is easily displaced onto nonhuman entities or objects. Most significantly, we have evidence from the neurophysiology of mirror neurons that empathy is to some extent hardwired into the brain. At least, it’s a better-documented biological property than obedience (which, as I recall from raising my own children, was not particularly reliable).

Within this framework Dawkins considers the problem of morality. Moral behavior is clearly not an inevitable result of religion—which seems to provoke more barbarism than it prevents—but it’s also not immediately obvious how a Darwinian regime would foster kindness and charity. While considering the ideas of kin selection and reciprocal altruism as reasonable mechanisms for introducing moral behavior, Dawkins again proposes that a wider morality, applied to more than just relatives and trusted friends, is a byproduct, an accidental gift of nonspecific feelings of generosity or sympathy. This implies that altruism imposes a negligible cost, that it’s an innocuous fluke. But I think we need a little something more to maintain altruism than to call it a lucky mistake—self-sacrifice for the benefit of unrelated individuals ought to be selected against. The maintenance of empathy as a tool for learning by emulation, and for enabling social interaction, would also produce the golden rule as a byproduct and would confer a benefit on those who possess it.

Near the end of The God Delusion, Dawkins asks some crucial questions: Why confront religion, and why should we be hostile to it? One could suggest that a similar book be written about, for instance, poetry, by someone who disliked it. The author would summarize the arbitrary rules used to arrange words as unfounded in logic and evidence, speculate about the evolutionary forces producing impersonal cognitive resonances that make it appealing to some, and propose that his readers would favor only unmetered, unrhymed prose once they had put his book down. Such a book might reasonably be read as the work of a crank.

Dawkins, however, is no crank, and he is not proposing the abolition of religion, but rather that we acquire a proper perspective on it. Religion is a cultural heritage that should be appreciated for its contributions to history, literature, and art, and Dawkins actually advocates more education in the subject. At the same time, its promotion as a guide to absolute truth, as a dogmatic and authoritarian prescription for behavior, and as a substitute for scientific thinking, leads to catastrophic excesses and false conclusions, which he documents at length. We can respect poetry as a window on the human mind and an outlet for the expression of beauty, but we’d laugh at someone who claimed that poetry explained cosmology, was grounds for declaring war, or could cure cancer. But religion makes these kinds of claims, and a dangerous majority accepts them. Dawkins asks that we recognize religion as a legitimate expression of human feeling—but that we avoid overendowing it with powers it does not possess.

The God Delusion is a powerful argument for how to think about the place of religion in the modern world. It’s going to be a classic, fit to stand with Sagan’s Pale Blue Dot and The Demon-Haunted World as a call to reason and Enlightenment values.